Spring mechanism for oil well devices



Oct. 1. 1940. H. HUGEL SPRING MECHANISM FOR OIL WELL DEVICES Filed June 8, 1939 2 Sheets-Sheet 1 nvenfor: Helmuf Huge! 51; his Aflorneq Oct. 1. 1940. H. HUGEL SPRING MECHANISM FOR OIL WELL DEVICES 2 Sheets-Sheet 2 Filed June 8, 1939 m U H m 0. m m m Patented Oct. 1, 1940 UNITED STATES PATENT OFFICE SPRING MECHANISM FOR OIL WELL DEVICES llelmut H-iigel, Campina, Romania, assignor to Shell Development Company, San Francisco,

ZClaims.

This invention relates to spring-impelled clockwork mechanisms and pertains more particularly to a clockwork driving mechanism for oil well devices, such as pressure or temperature recorders.

It is known in the art to employ spiral leaf springs under tension to move a stylus with regard to a strip of paper in contact therewith in order to obtain a chart recording a variable. such as pressure or temperature, with respect to the time element. Due, however, to the limited maximum diameter of the devices capable of being lowered into oil wells, it is difficult to store in a clockwork spring mechanism an amount of energy sufilcient for satisfactory operation. These mechanisms, therefore, either fail to exert the necessary force to overcome the friction encountered in moving the desired parts with regard to each other while making a record, or suc- 2Q ceed in exerting such force only for relatively short periods of time so that the useful operation time of the device is unduly restricted.

Thus. a strong spring mechanism, while capable of exerting a suil'nient force for eilectiveg5 ly actuating all the neces... ry working parts oi a recording mechanism to produce the desired record, usually dissipates its energy too quickly to permit a complete survey oi the conditions prevailing in a well to be eilected in one run, since a total of only about three or four revolutions oi the recording spindle or shaft can be obtained with such a spring. On the other hand, a weak spring mechanism, capable of giving six or more revolutions of the recording spindle, fails to exe'rt the iorce necessary to overcome the friction of the working parts and to effectively actuate said parts in such a manner as to produce the desired record. 1

It is, therefore, an object of this invention to provide an actuating mechanism for oil well recording devices comprising a plurality oi spiral leaf springs axially arranged in series in such a manner as to be lodged in a housing of relatively small diameter.

It is another object of this invention to provide an actuating mechanism for oil well recording devices comprising a plurality of relatively strong spiral leal springs coupled with each other in series, whereby the iorce exerted by said spring coupling arrangement is suiilcient to actuate the recording device throughout the whole period of operation of said device, while said period of operation of the device is substantially equal to the sum of the periods of operation or the individual springs forming said coupling.

It is another object of this invention to provide an actuating mechanism for oil well recording devices especially suitable for use in connection with the pressure and temperature recorders described in my co-pending applications Serial No. 184,780, filed January 13, 1938, and Serial No. 247,749, filed December 27, 1938, respectively.

. Further objects and advantages of the invention will be apparent from the following description taken in connection with the accompany- 1o ing drawings, wherein:

Figure 1 is a schematic longitudinal cross-sectional view of the upper portion of a preierred embodiment of a pressure recorder of my abovementioned co-pending application Serial No. 184,780.

Figure 2 is a longitudinal cross-sectional view of the lower portion of the same embodiment, particularly showing the present actuating mechanism. go

Figure 8 is a longitudinal cross-sectional view of the first or any intermediate spring case or housing, with the leaf spring and a portion of its ball races removed.

Figure 4 is a transverse cross-sectional view so taken along the line IV-IV oi Figure 8.

Figure 5 is a longitudinal cross-sectional view of the last or lowermost spring case and case lock container, with its leaf spring, a portion oi the ball races, ,studs and helical springs removed.

Figure 6 is a transverse cross-sectional view taken along the line VI-VI of Figure 5 with the studs and helical springs shown in place.

Figure 7 is an end view of the lock ring.

Figure 8 is a longitudinal cross-sectional view 5 taken along the line VIII-VIII of Figure 7.

Figure 9 is an end view of the ratchet wheel holder.

Figure 10 is a longitudinal cross-sectional view taken along the line x-x of Figure 9. showing also the ratchet wheel as inserted into the holder.

Figure 11 is a transverse cross-sectional view taken along the line XI-Xl of Figure 2.

' Referring first to Figures 1 and 2 of the drawings, parts i-Il inclusive represent schematical-. iv a pressure recorder of my above-mentioned application. Briefly, chart I records thereon the compound movement of a stylus 2, which is attached to shaft I of pressure-responsive piston l. The iluid pressure within the well is impressed so on the piston I from outside the device through ports I and is transmitted by means of diaphragm i to liquid filling the chamber I, tube l, and chamber I, containing also piston l, which moves axially against the spring II in response to pressure changes of the fluid. The time element is recorded on the chart i and static friction of the pressure-responsive piston 4 is minimized by means of the rotational motion imparted by the actuating spring mechanism of the present invention to the recorder stylus 2 and spindle ll through spring i0, piston 4 and shaft 2, as explained in my above-mentioned application Serial No. 184,780.

The recorder spindle II is supported at its lower end by ball race l2 and is attached to the upper end of a clock axis or shaft II of the present spring mechanism by means of a coupling l4 or any other suitable means. About the clock axis l3, which runs axially within the tubular housing It, are fitted spring cases or housings l8, l1 and I8 containing spiral leaf springs i9. 20 and 2 I, said cases being rotatably aligned with each other by means of ball bearings 2241 inclusive. The spring mechanism is protected from contamination by the well fluid by means of an nd case plug 28 which fits slidably about the clock axis or shaft 13 and within the housing It.

Referring to the more detailed illustrations in Figures 3, 4, and 5, the upper spring case it (similar to spring case l1), shown with the spring. and a portion of the ball racesremoved, consists of a tubular member having a portion it of enlarged diameter, and a portion Ila of reduced diameter. The tubular portion I8 is turned to an outside diameter suitable for slidably fitting within casing l5, and has an inside bore suitable for forming a housing for ball bearlugs 22 and 23, by means of which the spring case is rotatably mounted on the clock axis l2, and for spring l8 (not shown in Figure 3) mounted in the space defined by the case IS, the clock axis l3, and ball bearings 22 and 23. The tubular portion [8a is turned to an outside diameter permitting it to be inserted within the next spring case I! and within theleaf spring 20 contained in said case H. The tubular portion "a has also an internal bore l8b adapted to fit slidably around clock axis l3. The outer end of spiral leaf spring i8 is attached to the case it by means of a spring holding nut 29. shown in Figures 3 and 4, while its inner end is held to the clock axis II by means of a barb 32 on said axis. The spring 20 within case H (as well as all other springs except the above-mentioned uppermost spring I8) is held in the same manner, except that its inner end is not affixed to a barb on the clock axis, but to a barb 30 on the member lea of the preceding case projecting into case II. In this manner, it will be seen that the spring cases are adapted for rotational motion with regard to each other, to the casing l5, and to the clock axis ii.

The lowermost spring case I! (shown in detail in Figures 5 and 6) consists of an upper portion serving as a housing for the lowermost spring 2| and similar to the portion ll of the first and following spring cases, and of a lower portion 32 of solid cross-section, but provided with a bore 23b fitting slidingly around a tube 24a which in turn flts slidlngly around the clock axis l2; said lower portion is also provided. with slots 32a,

against the tube 24a, surrounding the clock axis ll.

Within the lowermost spring case It is a lock ring 21 (shown in Figures 7 and 8) having a cen-.

tral bore fitting slidably around the clock axis and fastened to the upper face of the solid body of the case lock container by means of screws in holes Ila. This lock ring prevents any upward axial displacement of the studs 34 and the tube 24a. The downward axial displacement of the studs 24 is prevented by a ratchet wheel holder 30 (shown in Figures 9 and 10), attached to the lower face of the solid body of the case lock container by means of screws in holes 38a. This holder is generally similar to the lock ring 21, but is provided with a square axial opening 38b adapted to receive a square cross-section pro- Jection 28a of a-ratchet wheel 89 which is mounted on the clock axis I! (as shown in Figure 10). Cross-sections along the lines X-X and Y--Y in Figures 7 and 9, respectively, correspond to the view of these parts shown in Figure 2.

Rotatably mounted within the casing below the ratchet wheel 38 is a clockwork movement 40, comprising upper and lower plugs 41 and 42, a concentric tubular holder 48, serving as a protective tube or housing for said clockwork movement, and movement plates 48. The upper and lower plugs 4| and 42, consist of cylindrical members, having ivo parallel longitudinal portions cut away fromeach plug to form a narrowed portion 41 with parallel faces. The narrowed portions 41 of the plugs face each other and fastened to the parallel faces thereof are the movement plates 48, which are thereby carried between the plugs 4| and 42. The remaining cylindrical portion 41a of the plugs has the tubular holder 48attached thereto. As shown in Figure 11, attached to the upper face of plug 4! is a pawl 42 pi'voted by means of a pawl pin 44 and held against the ratchet wheel 33 by means of a pawl spring 45 likewise attached to the upper plug 4i. The pawl engages the ratchet wheel in such manner that the clockwork movement 40 is permitted to rotate with regard to the last or stationary leaf spring case only in one direction, that is, the direction in which springs i8. and 2| spiral inward. The upper plug 4| has an axial bore which permits slidable passage therethrough of the clock axis or shaft i8.

The clockwork movement 40 further comprises a series of gears and wheels pivotably mounted between the movement plates 48 and operatively connected to a main spring arbor 'gear 49 on the lower end of the clock axis II by means of a main mitre gear 80. Reducing gears 6i permit the main mitre gear 50 to actuate the timing or escapement mechanism which comprises an escape wheel 52, a pallet fork 88, a balance wheel '4, and a hair spring 55.

A threaded bore into the lower transverse face of the lower movement case 42 permits the attachment of a winding spindle 5B which extends downward, carries bumpers 51 of resilient material, such as rubber, and terminates in a winding nut 58. A tubular member 59 is threadably connected to the housing It and forms a housing for the bumpers B1 and is provided with an internal shoulder or portion of narrowed bore, which serves as a stop for the bumpers 81 which in turn support the clockwork movement. A bottom plug 60 f is threadably attached to the lower end -'of the tubular member 59.

To wind the clock mechanism, which is assembled as described above, the bottom plug 60 is removed and by means of a key, winding nut 58 is revolved, which turns the winding spindle 5B, clockwork movement 40, clockwork axis l3, and spring cases i6, i1 and i8, whereby the spiral leaf springs i9, 20 and 2| are tensed in the order named. Then the bottom plug 60 is replaced and the recorder with the improved spring mechanism of the present invention is ready to be lowered into the borehole by means of a wire line or other suitable means. Release of the energy thus stored in the springs during operation causes a rotation of the clock axis or shaft [3 through the timing mechanism of the clockwork movement as the stationary ratchet 39 and pawl 43 rigidly engage the clockwork movement holder with the last or stationary spring case or holder and prevent release of the tension by turning of the clockwork movement and winding spindle 56 in adirection opposite to the winding direction.

Although the spring mechanism hereinabove illustrated and described contains, for purposes of simplicity, only three spiral leaf springs, it is to be understood that a greater or lesser number of such springs may be used while maintaining the principle of a plurality of springs coupled in series, two being obviously the minimum number of springs capable of useful application with the arrangement described above. In practice a device of the present invention containing six spiral leaf springs coupled in series has been found to be a preferred form for obtaining complete recordings throughout the length of deep wells. Normally with this arrangement the clockwork mechanism is so geared that the clock axis completes one revolution in about thirty minutes and with springs of suitable strength, the mechanism can make about twenty to twenty-five revolutions in a running time of about twelve hours and is able to pull a load of about 3 kg. on the circumference of a drum of 25 m. m. diameter fastened to the clock axis, when fully wound up, and over 2 kg. Just before being completely unwound. This force has been found to be about two to three times greater than the maximum required to turn the spindle of the pressure recording element referred to above. In another variation of this preferred form, with the reducing gears ii in the clockwork movement having a ratio of about 1,500, the total running time was about two and one-half to three days.

Although the embodiment herein disclosed is shown as applied to a well pressure recorder of my above-mentioned co-pending application, it is intended that the present spring mechanism may be coupled to other well pressure and temperature recorders and the like which require rotary motion for operation, since it is understood that the applicant is not limited to the particular type of construction shown in the drawings but may use any other embodiment to carry his invention into practice while applying the principle of the present invention.

I claim as my invention:

1. In a recording device adapted for operation in boreholes and comprising a cylindrical casing and a rotatable axial shaft within said casing, an actuating mechanism for said shaft, said mechanism comprising a plurality of spiral leaf springs mounted axially in series around the shaft, cylindrical housings for said springs having enlarged hollow portions slidably fitting within the easing and surrounding said springs, each of said housings excepting the last having a reduced portion slidably fitting around the shaft and projecting within the enlarged portion of the next housing, means attachingthe outer end of the first spring to the enlarged portion of its housing and its inner end to the shaft, means attaching the outer end of each succeeding spring to the enlarged portion of its housing, and its inner end to the reduced portion of the preceding housing, means fixedly attaching the last housing to the casing, each of said housings except the last being rotatable with regard to the casing, to the shaft, and to the other housings, and means for tensing the springs by rotating the shaft.

2. In a recording device adapted for operation in boreholes, a fluid tight casing containing recording members comprising a chart and a marker in contact with each other, one of said members being fixedly attached to the casing, and the other member being attached to an axial shaft rotatable within said casing, an actuating mechanism for said shaft, said mechanism comprising a plurality of spiral leaf springs mounted axially in series around said shaft, cylindrical housings for said springs having enlarged hollow portions slidably fitting within'the casing, each of said housings excepting the last having a reduced portion slidably fitting around the shaft and projecting within the enlarged portion of the next housing, whereby each spring is held in a space defined by the inner cylindrical wall of the enlarged portion of its housing and by the outer cylindrical wall of the reduced portion of the preceding housing, means attaching the outer end of the first spring to its housing and the inner end to the shaft, means attaching the outer end of each succeeding spring to its housing and the inner end to the reduced portion of the preceding housing, means fixedly attaching the last housing to the casing, anti-friction bearings between the housings permitting their free rotation with regard to each other, means for tensing the springs by rotating the shaft, and a clockwork escapement mechanism in meshing engagement with the shaft whereby said shaft is caused to rotate at a uniform rate in the other direction when the tension on the springs is released.

ammo-r HtiaEL. 

